Transmission for a hybrid drive arrangement, hybrid drive arrangement, vehicle, method for operating the hybrid drive arrangement, computer program and storage medium

ABSTRACT

The invention relates to a transmission (100) for a hybrid drive arrangement which can be coupled to two drive assemblies (7, 8), comprising an input shaft (10), and an output shaft (11), at least one first, second and third shifting element (SE1, SE2, SE3), and at least one first planetary gear (5). The input shaft (10) can be coupled to a first transmission shaft (16) by means of the first shifting element (SE1). The first transmission shaft (16) can be coupled to the sun gear of the planetary gear (5) by means of the second shifting element (SE2) and the ring gear of the planetary gear (5) is coupled to the first transmission shaft (16). The input shaft (10) can be coupled to the sun gear of the planetary gear (5) by means of the third shifting element (SE3). The output shaft (11) is coupled to the planet carrier of the planetary gear (5).

BACKGROUND OF THE INVENTION

The invention relates to a transmission for a hybrid drive arrangement.Furthermore, the invention relates to a hybrid drive arrangement havinga transmission, to a vehicle having a hybrid drive arrangement, and to amethod for operating the hybrid drive arrangement, and to a computerprogram and a machine-readable storage medium.

Transmissions for hybrid drive arrangements are known from the priorart. For example, WO2010/009943 A1 discloses a double clutchtransmission which makes the operation of a hybrid vehicle possible byway of internal combustion engine, by way of electric motor, and by wayof the two drive units together. Transmissions of this type are complex,heavy and expensive. There is a requirement for transmission topologieswith a reduced mechanical complexity, a decreased installation spacerequirement and a reduced weight.

In the following text, the term “coupled” or “attached” is used in thesense of a fixed connection. In contrast to this, the term “can becoupled” comprises both fixed and switchable connections within thecontext of the present description. If a switchable connection isspecifically meant, the corresponding shifting element is as a rulespecified explicitly, in particular a brake or a clutch. If, incontrast, a fixed, rigid or non-rotating connection is specificallymeant, the term “coupled” or “attached” is as a rule used and the use ofthe term “can be coupled” is dispensed with. The use of the term “can becoupled” without specification of a specific shifting element thereforeindicates the intentional inclusion of the two types. This distinctiontakes place solely for the benefit of improved comprehensibility and, inparticular, in order to clarify where the provision of a switchableconnection instead of a fixed connection or coupling which can as a rulebe realized more easily is absolutely necessary. The above definition ofthe term “coupled” or “attached” is therefore in no way to beinterpreted to be so narrow that couplings which are insertedarbitrarily for bypassing purposes are derived from its literal sense.

SUMMARY OF THE INVENTION

A transmission for a hybrid drive arrangement is provided, whichtransmission can be coupled to two drive units, having an input shaftand an output shaft, at least a first, second and a third shiftingelement, and at least one planetary transmission,

it being possible for the input shaft to be coupled by means of thefirst shifting element to a first transmission shaft and it beingpossible for the first transmission shaft to be coupled by means of thesecond shifting element to the sun gear of the planetary transmission,the internal gear of the planetary transmission being coupled to thefirst transmission shaft, and it being possible for the input shaft tobe coupled by means of the third shifting element to the sun gear of theplanetary transmission

and the output shaft being coupled to the planetary carrier of theplanetary transmission.

A transmission for a hybrid drive arrangement is provided. For theoperation of the hybrid drive arrangement, two drive units can becoupled to the transmission. The transmission comprises an input shaftand an output shaft, at least a first, second and a third shiftingelement, and at least one planetary transmission. By means of closing ofthe first shifting element, the input shaft can be coupled to a firsttransmission shaft. By means of closing of the second shifting element,the first transmission shaft can be coupled to the sun gear of theplanetary transmission. The internal gear of the planetary transmissionis fixedly coupled to the first transmission shaft. Within the contextof the description, a coupling is to be understood as being a connectionwhich is configured rigidly, for example in one piece, for example bymeans of a shaft, or with a fixed transmission or transmission stage.Furthermore, the input shaft can be coupled by means of the thirdshifting element to the sun gear of the planetary transmission. Theoutput shaft is coupled to the planetary carrier of the planetarytransmission. In particular, the output shaft can be coupled to anoutput. The output is, in particular, a shaft or an axle which transmitsthe movement of the output shaft to the mechanical drive train of avehicle, for example to a differential or to a drive wheel. Atransmission is advantageously provided which transmits the rotationalspeed and the torque which prevails at the input shaft to the outputshaft in accordance with the transmission ratios in the transmission inthe case of a closed first, second and/or third shifting element. In thecase of an open first and third shifting element, the input shaft isdecoupled from the output shaft.

In another refinement of the invention, the transmission comprises afourth shifting element which is set up to brake or to release the sungear of the planetary transmission.

A fourth shifting element is provided for the transmission, which fourthshifting element makes releasing or braking of the sun gear of theplanetary transmission possible, in particular connecting of the sungear or supporting of the sun gear on a fixed point or on a housing ofthe transmission. The braking of the sun gear comprises the reduction ofthe rotational speed of the sun gear, in particular to a standstill ofthe sun gear. The releasing of the sun gear comprises the releasing ofthe brake, with the result that the sun gear accelerates in accordancewith the forces which act on the sun gear. In addition to theabovementioned operating modes, further operating modes canadvantageously be set by way of the above-described topology of thetransmission with the first to fourth shifting elements. The highestpossible transmission ratio which can be achieved with this transmissionbetween the input shaft and the output shaft thus results in the case ofclosed first and fourth and open second and third shifting elements.

In a further refinement of the invention, the first, second and/or thethird shifting element comprise/comprises a clutch.

In order to connect the input shaft to the aforementioned components ofthe planetary transmission and the first transmission shaft, the first,second and/or the third shifting element are/is configured as a clutch.A clutch of this type can be, in particular, a dry clutch, a wet clutchor a claw coupling. Possibilities for a controllable connection of theinput shaft to the components of the planetary transmissions and thefirst transmission shaft are advantageously provided.

In another refinement of the invention, the fourth shifting elementcomprises a brake.

The fourth shifting element is configured as a brake, in particular as adry brake or wet brake or as a claw coupling. A possibility forcontrollably releasing and braking the sun gear of the planetarytransmission is advantageously provided.

In another refinement of the invention, a first drive unit, inparticular an internal combustion engine, can be coupled to the inputshaft, and/or a second drive unit, in particular an electric machine,can be coupled to the first transmission shaft.

The first drive unit can be attached on the input shaft on the inputside. The second drive unit can be coupled to the first transmissionshaft. For generator operation of the second drive unit, for example anelectric machine, for example in order to charge a battery, the firstdrive unit or the internal combustion engine can advantageously beconnected to the electric machine by means of closing of the firstshifting element and opening of the second, third and fourth shiftingelement. Since the two drive units are decoupled here from the outputshaft and therefore no torque is transmitted to the output shaft, saidcharging can take place in the case of an output shaft which is at astandstill, for example, that is to say, for example, during thestandstill of a vehicle (standstill charging). In the case of an outputshaft which is, for example, at a standstill, a direct transmission ofthe rotational energy of the first drive unit to the second drive unitor vice versa is made possible, for example in order to start aninternal combustion engine.

Power-split operation of the transmission (eCVT mode) is made possibleby way of closing of the third shifting element and opening of thefirst, second and fourth shifting element. Here, the first drive unitacts on the sun gear of the planetary transmission and the electricmachine acts on the internal gear of the planetary transmission, theplanetary carrier of which is connected to the output shaft. Here, thetransmission ratio between the input shaft and the output shaft can bevaried continuously over a wide range by means of specification of arotational speed or a torque of the second drive unit. Power-splitoperation (also called eCVT mode) is advantageously made possible, inthe case of which both the propulsion power at the output shaft and thecharging power for the generator operation of the electric machine canbe set independently of one another. Charging at a standstill or incrawling mode (>0 km/h to approximately 10 km/h) and a smoothcomfortable transition from the standstill charging mode into thecrawling charging mode and the driving mode is advantageously madepossible with a fixed transmission, that is to say in a fixed gear.

In the case of an open first and third shifting element, the input shaftand therefore the first drive unit are decoupled from the output shaft.In the case of an additionally closed fourth or second shifting element,the second drive unit is connected via a first or second transmission tothe output shaft, with the result that driving of the output shaft cantake place only by means of the second drive unit with two differenttransmissions. By means of (in particular, metered) closing of the firstshifting element, the first drive unit can be driven and, for example,can be started if the first drive unit is an internal combustion enginewhile driving by means of the second drive unit.

There is also the possibility that the first drive unit is configured,for example, as an electric machine, and the second drive unit isconfigured, for example, as an internal combustion engine. In aconfiguration of this type, different functionalities and operatingmodes for the interaction of the components can result by means of thetransmission, which are not described further here.

In another refinement of the invention, the transmission ratios of thetransmission are changed without the traction force being interrupted.

Changing of the transmission ratios of the transmission, in particularshifting into another gear or into another operating mode of thetransmission, takes place without the traction force being interruptedif, in particular, for the change from one operating mode of thetransmission into another, one of the shifting elements retains itsstate, a second one of the shifting elements is transferred from aclosed state into an open state, and a third one of the shiftingelements is transferred from an open state into a closed state. Atransmission is advantageously provided, in the case of which changingof the gear stages without an interruption of the traction force is madepossible.

In another refinement of the invention, the transmission comprises anactuator for actuating at least one of the shifting elements in a mannerwhich is dependent on a predefined operating specification signal.

An actuator is provided which actuates at least one of the shiftingelements in a manner which is dependent on a predefined operatingspecification signal, for example a requested torque, a predefinedrotational speed, or a defined operating point of the drive unit. Saidparameters of the operating specification signal can be related to theoutput shaft of the transmission, to the input shaft, or to the shaftswhich are to be connected to the drive units. Control of thetransmission is advantageously made possible.

Furthermore, the invention relates to a hybrid drive arrangement havinga transmission, the hybrid drive arrangement comprising a second driveassembly and/or a pulse inverter, an electric energy source or a firstdrive unit.

A hybrid drive arrangement having an above-described transmission isprovided. The hybrid drive arrangement comprises a second driveassembly. In particular, the hybrid drive arrangement comprises a pulseinverter, an electric energy source and/or a first drive unit. Thesecond drive unit is coupled or connected, in particular, to the firsttransmission shaft. The pulse inverter is provided, in particular, forsupplying the second drive unit, in particular an electric machine. Tothis end, in particular, it converts the electric energy of an electricenergy source, for example a battery and/or a fuel cell. The first driveunit is coupled or connected, in particular, to the input shaft. Ahybrid drive arrangement which is set up for use in a vehicle isadvantageously provided.

Furthermore, the invention comprises a vehicle having a described hybriddrive arrangement. A vehicle which comprises a hybrid drive arrangementis advantageously provided.

Furthermore, the invention comprises a method for operating a hybriddrive arrangement having a transmission. The method comprises thefollowing steps:

determining of an operating specification signal;

actuating of at least one of the shifting elements in order to set thefunctionality of the transmission in a manner which is dependent on theoperating specification signal (BV).

A method for operating a hybrid drive arrangement having a transmissionis provided. Here, an operating specification signal is determined. Atleast one of the shifting elements is closed or opened in order to setthe functionality of the transmission or of a corresponding operatingmode in a manner which is dependent on the operating specificationsignal. The operating specification signal is predefined in a mannerwhich is dependent on an operating strategy, a driver request oraccelerator pedal, a battery management system or other systems whichare available, for example, in a vehicle. In a manner which is dependenton said operating specification signal, the shifting elements areactuated in order to set the corresponding functionality or theoperating mode of the transmission, in particular the clutches or brakesare closed or opened. The functionality of the transmission or theoperating mode are, in particular, the different transmission ratios ofthe various gear stages, or the various modes or operating modes, forexample generator operation of the second drive unit in the case of astationary output shaft or the eCVT mode. A method for operating ahybrid drive arrangement is advantageously provided.

Furthermore, the invention relates to a computer program which is set upto carry out the described method.

Furthermore, the invention relates to a machine-readable storage medium,on which the described computer program is stored.

BRIEF DESCRIPTION OF THE DRAWINGS

It goes without saying that the features, properties and advantages ofthe transmission relate and/or can be applied accordingly to the hybriddrive arrangement, the vehicle and/or the method, and vice versa.Further features and advantages of embodiments of the invention resultfrom the following description with reference to the appended drawings.

In the following text, the invention is to be described in greaterdetail on the basis of some figures, in which:

FIG. 1 shows a diagrammatic illustration of the hybrid drive trainarrangement having a transmission,

FIG. 2 shows a shifting matrix of the transmission,

FIG. 3 shows a diagrammatically illustrated vehicle having a hybriddrive train arrangement, and

FIG. 4 shows a diagrammatically illustrated method for operating ahybrid drive train arrangement.

DETAILED DESCRIPTION

FIG. 1 shows a hybrid drive train arrangement 200 having a first driveunit 7, in particular an internal combustion engine, and a second driveunit 8, in particular an electric machine, and a transmission 100. Inparticular, the hybrid drive train arrangement comprises a pulseinverter 60 for supplying the second drive unit 8 with electric energy.Furthermore, the hybrid drive train arrangement 200 comprises, inparticular, an electric energy source 70 which is connected to the pulseinverter 60. The transmission 100 comprises the input shaft 10 and theoutput shaft 11. Furthermore, the transmission 100 comprises a planetarytransmission 5. Furthermore, the transmission 100 comprises a first, asecond and a third shifting element SE1, SE2, SE3. The first shiftingelement SE1, in particular a clutch, is set up to connect or todisconnect the input shaft 10 to/from a first transmission shaft 16. Thefirst transmission shaft is connected to the internal gear of theplanetary transmission 5. The second shifting element SE2, in particulara clutch, is set up to connect or to disconnect the first transmissionshaft 16 to/from the sun gear of the planetary transmission 5. The thirdshifting element SE3, in particular a clutch, is set up to connect or todisconnect the input shaft 10 to/from the sun gear of the planetarytransmission 5. Furthermore, the transmission 100 can comprise a fourthshifting element SE4. The fourth shifting element SE4, in particular abrake, is set up to release or to brake the sun gear of the planetarytransmission 5, in particular by the brake connecting the internal gearto a fixed point or, for example, supporting it on the housing (notshown) of the transmission 100. The first transmission shaft 16 iscoupled to the internal gear of the planetary transmission 5.Furthermore, the transmission is set up to be coupled or connected to afirst drive unit via the input shaft 10 for operation. To this end, FIG.1 shows that the shaft of the drive unit 7 is connected directly to theinput shaft 10. The second drive unit 8, in particular an electricmachine, is connected to the first transmission shaft 16 for theoperation of the transmission 100, as shown in FIG. 1. For anoptimization of the transmission ratios, the output shaft 11 isconnected, for example, to a differential 14, for example via an output12, in particular a spur gear set, via which differential 14 themovements are transmitted to the wheels 310. An actuator 50 is providedfor actuating the shifting elements, which actuator 50 carries out themethod for operating the hybrid drive arrangement having thetransmission. The control lines between the actuator 50 and theindividual shifting elements SE1 . . . SE4 are indicated only as anarrow and are not fully illustrated for reasons of clarity. Thecommunication between the shifting elements SE1 . . . SE4 and theapparatus can take place by means of the control lines but also by meansof a bus system or in a wireless manner.

FIG. 2 shows a shifting matrix of the transmission. The individualshifting elements SE1 . . . SE4 are indicated in the columns, and anapproximate transmission ratio which results between one of the driveunits and the output shaft is shown in the last column by way ofexample. The different gear stages, gears or operating modes of thetransmission are indicated in the rows. Crosses in the shifting matrixshow which of the shifting elements have to be activated, in order thatthe corresponding gear or operating mode is set. Here, activation of theshifting elements means, in particular, that a clutch is closed or abrake is actuated, with the result that a force can be transmitted viathe clutch from one shaft to a further shaft or a force can betransmitted by means of the brake to a fixed point, in particular thetransmission housing. It can be seen from the shifting matrix that,depending on the combination of the four shifting elements, four gearsG1 . . . G4 can be set, the first gear G1 having the highesttransmission ratio and the fourth gear G4 having the lowest transmissionratio. In the case of the gears G1 . . . G4, there is preferably in eachcase a fixed rotational speed ratio between the first drive unit 7 andthe output shaft 11 in accordance with the transmission given in thelast column. The output shaft is driven in the gears G1 . . . G4 eitherby the first drive unit 7 alone or together with the second drive unit8. In particular, these are internal combustion engine or hybrid gears,for example if the first drive unit 7 is an internal combustion engineand the second drive unit 8 is an electric machine. Said gears also makeit possible to raise the load point of the internal combustion engine,with the result that the electric machine can be operated as agenerator, and charging of a battery can take place during operation, inparticular driving operation of a vehicle. The gears E1 . . . E2 oroperating modes, in which only the second drive unit 8 is connected tothe output shaft 11, are also shown in the following lines of thematrix. To this end, in particular, the first and the third shiftingelement SE1, SE3 has to be open, in order that there is no connection tothe first drive unit 7. These are, in particular, electric motor gears,for example if the second drive unit is an electric machine. A vehiclecan advantageously be operated locally without emissions in said gears.Depending on whether the sun gear of the planetary transmission 5 isblocked by means of the fourth shifting element SE4 or the internal gearof the planetary transmission 5 is blocked by means of the secondshifting element SE2, the transmissions given in the shifting matrixresult between the second drive unit 8 and the output shaft 11, by wayof example.

Closing of the third and opening of the other shifting elements (SE1 . .. SE4) results in power-split operation, the eCVT1 mode which makes amutually independent propulsion power at the output shaft 11 andcharging power of the second drive unit 8 possible. In particular, saidoperating mode is suitable for hybrid driving off in the case of a lowbattery charging state, since stepless changing of the transmissionratios and therefore, in particular, stepless acceleration are possiblein the case of a simultaneous generator operation of the second driveunit 8.

A further mode CH1, also called standstill charging, results if thefirst shifting element SE1 is closed and all other shifting elements areopen. Here, the drive units 7 and 8 are coupled to one another, therenot being a connection to the output shaft 11. In said operating mode,the second drive unit 8 can be driven by means of the first drive unit 7during the standstill of the output shaft, in particular of a vehicle,in particular can be used in the manner of a generator for charging anelectric energy source 70, in particular a battery. As an alternative,the first drive unit 7 can also be driven by means of the second driveunit 8, and, for example, an internal combustion engine start or adiagnosis of the internal combustion engine can be carried out if thefirst drive unit 7 is an internal combustion engine and the second driveunit 8 is an electric machine.

FIG. 3 shows a vehicle 300 with wheels 310, the vehicle comprising ahybrid drive arrangement 200, as described above.

FIG. 4 shows a flow chart of a method 400 for operating a hybrid drivearrangement 200 having a transmission 100. The method starts with step405. In step 410, an operating specification signal BV is determinedand, in step 420, at least one of the shifting elements SE1 . . . SE4 isactuated in order to set the functionality of the transmission 100 in amanner which is dependent on the operating specification signal BV. Themethod ends with step 425. Here, the operating specification signal BVis either a parameter for a physical variable in the transmission 100,such as a torque or a rotational speed or a power output to betransmitted which is to prevail at or to be transmitted to a componentof the transmission 100. Said components are, in particular, the inputshaft 10, the output shaft 11, but also the parameters at the driveunits 7, 8 or the shifting elements SE1 . . . SE4. Moreover, theoperating specification signal BV can also represent a defined operatingmode such as one of the four gears G1 . . . G4 or the two gears E1 . . .E2 which are operated only by way of the second drive unit, or else canrepresent the special functions eCVT1 or standstill charging CH1. In amanner which is dependent on said operating specification signal BV, theshifting elements SE1 to SE4 are actuated in accordance with theshifting matrix, in order to shift the transmission 100 into thecorresponding gear or operating mode. For a shift between the individualgears or operating modes with no interruption of the tractive force, itis necessary that one of the shifting elements SE1 . . . SE4 retains itsstate before and after the shifting operation, a further shiftingelement moving during the shifting from the open into the closed state,whereas another shifting element moves from the closed into the openstate.

The invention claimed is:
 1. A transmission (100) for a hybrid drivearrangement, the transmission (100) configured to be coupled to twodrive units (7, 8), the transmission comprising an input shaft (10) andan output shaft (11), at least a first, second and a third shiftingelement (SE1, SE2, SE3), and at least one planetary transmission (5),the transmission further configured to couple the input shaft (10) viathe first shifting element (SE1) to a first transmission shaft (16),couple the first transmission shaft (16) via the second shifting element(SE2) to a sun gear of the planetary transmission (5), an internal gearof the planetary transmission (5) being coupled to the firsttransmission shaft (16), couple the input shaft (10) to the thirdshifting element (SE3) to the sun gear of the planetary transmission(5), and couple the output shaft (11) to the planetary carrier of theplanetary transmission (5).
 2. The transmission as claimed in claim 1,further comprising a fourth shifting element (SE4) configured to brakethe sun gear of the planetary transmission (5).
 3. The transmission asclaimed in claim 1, wherein the first, the second, the third, or acombination of the first, second, and third shifting elements (SE1, SE2,SE3) comprise a clutch.
 4. The transmission as claimed in claim 2,wherein the fourth shifting element (SE4) comprises a brake.
 5. Thetransmission as claimed in claim 1, further configured to couple aninternal combustion engine to the input shaft (10), and couple anelectric machine to the first transmission shaft (16).
 6. Thetransmission as claimed in claim 1, wherein the transmission is furtherconfigured to change ratios of the transmission (100) without a tractionforce being interrupted.
 7. The transmission as claimed in claim 1,further comprising an actuator (50) configured to actuate at least oneof the shifting elements (SE1 . . . SE4) in a manner which is dependenton a predefined operating specification signal (BV).
 8. A hybrid drivearrangement (200) comprising: a transmission (100) including an inputshaft (10) and an output shaft (11), at least a first, a second and athird shifting element (SE1, SE2, SE3), at least one planetarytransmission (5), the transmission further configured to couple theinput shaft (10) via the first shifting element (SE1) to a firsttransmission shaft (16), couple the first transmission shaft (16) viathe second shifting element (SE2) to a sun gear of the planetarytransmission (5), an internal gear of the planetary transmission (5)being coupled to the first transmission shaft (16), couple the inputshaft (10) to the third shifting element (SE3) to the sun gear of theplanetary transmission (5), and couple the output shaft (11) to theplanetary carrier of the planetary transmission (5), a pulse inverter(60), and an electric energy source (70).
 9. A vehicle (300) having ahybrid drive arrangement (200) as claimed in claim
 8. 10. A method (400)for operating a hybrid drive arrangement (200) having a transmission(100) having an input shaft (10) and an output shaft (11), at least afirst, second and a third shifting element (SE1, SE2, SE3), at least oneplanetary transmission (5), the transmission further configured tocouple the input shaft (10) via the first shifting element (SE1) to afirst transmission shaft (16), couple the first transmission shaft (16)via the second shifting element (SE2) to a sun gear of the planetarytransmission (5), an internal gear of the planetary transmission (5)being coupled to the first transmission shaft (16), couple the inputshaft (10) to the third shifting element (SE3) to the sun gear of theplanetary transmission (5), and couple the output shaft (11) to theplanetary carrier of the planetary transmission (5), the methodcomprising: determining (410) an operating specification signal (BV),and actuating (420) at least one of the shifting elements (SE1 . . .SE4) in order to set the functionality of the transmission (100) in amanner which is dependent on the operating specification signal (BV).11. A non-transitory, computer-readable storage medium comprisingprogram instructions that when executed by a computer cause the computerto control a transmission that includes an input shaft (10) and anoutput shaft (11), at least a first, second and a third shifting element(SE1, SE2, SE3), at least one planetary transmission (5), thetransmission further configured to couple the input shaft (10) via thefirst shifting element (SE1) to a first transmission shaft (16), couplethe first transmission shaft (16) via the second shifting element (SE2)to a sun gear of the planetary transmission (5), an internal gear of theplanetary transmission (5) being coupled to the first transmission shaft(16), couple the input shaft (10) to the third shifting element (SE3) tothe sun gear of the planetary transmission (5), and couple the outputshaft (11) to the planetary carrier of the planetary transmission (5),wherein the program instructions, when executed by the computer, causethe computer to control the transmission by: determining (410) anoperating specification signal (BV), and actuating (420) at least one ofthe shifting elements (SE1 . . . SE4) in order to set the functionalityof the transmission (100) in a manner which is dependent on theoperating specification signal (BV).